【摘要】 目的　比较 40 96级灰度数字图像系统与 2 5 6级灰度系统显示铝阶的能力以及两种系统所照的临床图像。方法　用纯铝制作总高 30mm的铝阶 ,每阶高和宽均为 1mm。分别记录 40 96级灰度图像系统 (ODIS ,国产 )和 2 5 6级灰度图像系统 (DIGORA ,芬兰 )在上述条件下所能显示的铝阶数目。随机抽取这两个系统所照的临床X线图像共计 10 0幅 (ODIS 6 0幅 ,DIGORA 40幅 )进行评级。结果　在不同曝光条件下 40 96级灰度系统均比 2 5 6级灰度系统显示的铝阶数目多 10个以上 ,ODIS系统最多可以显示 2 8级铝阶 ,而DIGORA系统最多可以显示 12级。临床图像 40 96级灰度系统的图像Ⅰ级 5 6 (93.3% ) ,Ⅱ级 3(5 % ) ,Ⅲ级 1(1.7% ) ;2 5 6级灰度系统图像Ⅰ级 18(4 5 % ) ,Ⅱ级 18(4 5 % ) ,Ⅲ级 4(10 % )。结论　 40 96级灰度图像系统显示的信息量明显大于 2 5 6级灰度图像系统 ,有助于改善临床X线诊断质量更多还原

【Abstract】 Objective To compare display ability of 8 bit (256 degree gray level) dental X-ray imaging system and 12 bit (4096 degree gray level) dental imaging system with aluminum step and clinical dental images.Methods The 8-bit system is Digora (Sodex Finland) and the 12-bit system is ODIS (Fiscan,China).The aluminum step in the experiment is 30mm high with 30 stages,1mm per stage.The two systems used same X-ray source and exposure parameters.When images in each system were adjusted into best condition,the stage numbers of the aluminum step on the images were recorded.The qualities of clinical images were assessed.The 100 images were 60 images from ODIS and 40 images from Digora and were divided into 4 degrees.Results The stage numbers of the aluminum step in the images were shown 14 to 28 on ODIS system,while on the Digora system,the stage numbers were only shown 4 to 12. On the ODIS system,56 ( 93.3 %) clinical images were Ⅰ degree,3(5%) were Ⅱ degree,1( 1.7 %) was Ⅲ degree.On the Digora system,18(45%) were Ⅰ degree,18(45%) were Ⅱ degree,4(10%) were Ⅲ degree.Conclusion The 4096 gray level system could show more information than the 256 gray level system.更多还原